Junos OS (SRX firewalls)
CVE-2024-39556: Loading a malicious certificate from the CLI may result in a stack-based overflow
A Stack-Based Buffer Overflow vulnerability in Juniper Networks Junos OS and Juniper Networks Junos OS Evolved may allow a local, low-privileged attacker with access to the CLI the ability to load a malicious certificate file, leading to a limited Denial of Service (DoS) or privileged code execution.
Published
Automatic summary from the vendor's CVE record. We haven't written a full analysis of this vulnerability yet.
Affected and fixed versions
| Product / branch | Fixed in |
|---|---|
| Junos OS 0 | 21.4R3-S7 or later |
| Junos OS 22.1 | 22.1R3-S6 or later |
| Junos OS 22.2 | 22.2R3-S4 or later |
| Junos OS 22.3 | 22.3R3-S3 or later |
| Junos OS 22.4 | 22.4R3-S2 or later |
| Junos OS 23.2 | 23.2R2 or later |
| Junos OS 23.4 | 23.4R1-S1, 23.4R2 or later |
| Junos OS Evolved 0 | 21.4R3-S7-EVO or later |
| Junos OS Evolved 22.1-EVO | 22.1R3-S6-EVO or later |
| Junos OS Evolved 22.2-EVO | 22.2R3-S4-EVO or later |
| Junos OS Evolved 22.3-EVO | 22.3R3-S3-EVO or later |
| Junos OS Evolved 22.4-EVO | 22.4R3-S2-EVO or later |
| Junos OS Evolved 23.2-EVO | 23.2R2-EVO or later |
| Junos OS Evolved 23.4-EVO | 23.4R1-S1-EVO, 23.4R2-EVO or later |
Always confirm against the vendor advisory, which lists every fixed hotfix.
What it is
A Stack-Based Buffer Overflow vulnerability in Juniper Networks Junos OS and Juniper Networks Junos OS Evolved may allow a local, low-privileged attacker with access to the CLI the ability to load a malicious certificate file, leading to a limited Denial of Service (DoS) or privileged code execution.
By exploiting the 'set security certificates' command with a crafted certificate file, a malicious attacker with access to the CLI could cause a crash of the command management daemon (mgd), limited to the local user's command interpreter, or potentially trigger a stack-based buffer overflow.
This issue affects:
Junos OS:
- All versions before 21.4R3-S7,
- from 22.1 before 22.1R3-S6,
- from 22.2 before 22.2R3-S4,
- from 22.3 before 22.3R3-S3,
- from 22.4 before 22.4R3-S2,
- from 23.2 before 23.2R2,
- from 23.4 before 23.4R1-S1, 23.4R2;
Junos OS Evolved:
- All versions before 21.4R3-S7-EVO,
- from 22.1-EVO before 22.1R3-S6-EVO,
- from 22.2-EVO before 22.2R3-S4-EVO,
- from 22.3-EVO before 22.3R3-S3-EVO,
- from 22.4-EVO before 22.4R3-S2-EVO,
- from 23.2-EVO before 23.2R2-EVO,
- from 23.4-EVO before 23.4R1-S1-EVO, 23.4R2-EVO.
Workarounds
There are no known workarounds for this issue.
Exploitation
Juniper SIRT is not aware of any malicious exploitation of this vulnerability.
Sources
KEV status, EPSS score and vendor data refreshed automatically, last on 13 Oct 2026.